The degeneration of the intervertebral disk, in particular, the degeneration of the nucleus pulposus, results in a loss of height in the affected disk space which is associated with a weakening of the annulus fibrosus and of the ligaments. As a consequence, the spinal column becomes instable and is more susceptible to horizontal displacement of the vertebral bodies with respect to one another. This horizontal movement of the vertebral bodies results in impairments of the nerve roots in this region and/or of the spinal marrow, and in pain resulting from these impairments.
The principle treatment of these symptoms consists of the surgical removal of the nucleus pulposus and the insertion of support bodies in order to restore the normal height of the disk space. There are a variety of demands on both the surgeon performing an intervertebral procedure, and on the spinal spacers themselves.
A Transforaminal Lumbar Interbody Fusion (TLIF) is a surgical procedure that uses a posterior and lateral approach to access the disc space. To gain access to the disc space, typically a facet joint is removed and access is gained via the nerve foramen. While more technically demanding of the surgeon than other fusion techniques, a TLIF offers a number of clinical advantages. Specifically, when compared to a PosteroLateral Fusion (PLF), a TLIF approach leaves much more of the soft tissue intact, which is less traumatic for the patient. Further, a PLF does not provide sufficient access to the disc space for comprehensive evacuation of the disc.
While Posterol Lateral InterBody Fusion (PLIF) provides limited access to the disc space, a TLIF approach also provides access to the interbody space, but without the need for manipulation of neural elements, reducing the risk of post-operative neural deficit. Additionally, in TLIF, only a single spacer is placed. More specifically, the TLIF spacer is placed in the anterior aspect of the disc space, thus providing space for a substantial fusion mass in the posterior aspect of the disc space where the natural compression occurs.
Traditional TLIF procedures do, however, suffer from shortcomings. For example, to place the desired spacer in the anterior aspect of the disc space from an oblique posterior approach, traditional procedures demand that the spacer be released from the inserter and then tamped into place. This two step insertion of the spacer is generally recognized among surgeons as cumbersome. The problem of manipulating the spacer into the disc space may be exacerbated in patients where the iliac crest must be maneuvered around to place the implant.
Therefore, there is a need for a device, system and procedure to enable access to the area between the Lumbar spine, the L-2, and the Sacrum, the S1, from a lateral or posteriolateral approach. The system should provide insertion tooling that cooperates with an implant to allow a surgeon to pivot/orient the implant with respect to the insertion tool without fully releasing control of the implant. The system should allow the surgeon to positively re-engage/lock the implant to the insertion tool once the desired angle between the inserter and implant has been achieved. The release for rotation and re-locking of the implant with respect to the insertion tool should be repeatable as often as desired or needed by the surgeon. The insertion tool should be self contained and should not require excessive strength to operate.